U.S. patent number 10,396,429 [Application Number 16/190,454] was granted by the patent office on 2019-08-27 for wireless communication device.
This patent grant is currently assigned to MURATA MANUFACTURING CO., LTD.. The grantee listed for this patent is Murata Manufacturing Co., Ltd.. Invention is credited to Nobuo Ikemoto, Ikuhei Kimura.
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United States Patent |
10,396,429 |
Kimura , et al. |
August 27, 2019 |
Wireless communication device
Abstract
A compact wireless communication includes a first radiating
element and a second radiating element, which define and function
as a dipole antenna, a feeder circuit including a wireless IC chip
coupled with the first and second radiating elements, and a feeder
substrate that is provided with the wireless IC chip. The first
radiating element is provided to the feeder substrate. The second
radiating element is provided to a substrate other than the feeder
substrate.
Inventors: |
Kimura; Ikuhei (Nagaokakyo,
JP), Ikemoto; Nobuo (Nagaokakyo, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
Murata Manufacturing Co., Ltd. |
Nagaokakyo-shi, Kyoto-fu |
N/A |
JP |
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Assignee: |
MURATA MANUFACTURING CO., LTD.
(Kyoto, JP)
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Family
ID: |
46457403 |
Appl.
No.: |
16/190,454 |
Filed: |
November 14, 2018 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20190081383 A1 |
Mar 14, 2019 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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15368817 |
Dec 5, 2016 |
10164321 |
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14723486 |
Apr 25, 2017 |
9634376 |
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13795367 |
Sep 12, 2017 |
9761923 |
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PCT/JP2011/078263 |
Dec 7, 2011 |
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Foreign Application Priority Data
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Jan 5, 2011 [JP] |
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2011-000694 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01Q
9/16 (20130101); G06K 19/07794 (20130101); G06K
19/07773 (20130101); H01Q 9/065 (20130101); H01Q
1/38 (20130101); H01Q 1/2225 (20130101); G06K
19/07786 (20130101); G06K 19/07784 (20130101); H01Q
1/50 (20130101); G06K 19/07783 (20130101); H04W
4/80 (20180201) |
Current International
Class: |
H01Q
1/22 (20060101); G06K 19/077 (20060101); H01Q
1/50 (20060101); H01Q 1/38 (20060101); H01Q
9/16 (20060101); H01Q 9/06 (20060101); H04W
4/80 (20180101) |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Kimura et al., "Wireless Communication Device", U.S. Appl. No.
15/368,817, filed Dec. 5, 2016. cited by applicant.
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Primary Examiner: Johnson; Sonji N
Attorney, Agent or Firm: Keating & Bennett, LLP
Claims
What is claimed is:
1. A piece of merchandise including a wireless communication
device, comprising: a feeder substrate including a wireless IC
chip, a first radiating element connected to the wireless IC chip,
and a feeder terminal of a feeder circuit connected to the wireless
IC chip; and a packaging bag including a second radiating element;
wherein the feeder substrate is attached to the packaging bag, and
the feeder terminal of the feeder circuit is connected to the
second radiating element of the packaging bag via capacitive
coupling; and the first radiating element is included not in the
packaging bag but only in the feeder substrate.
2. A piece of merchandise including a wireless communication device
according to claim 1, wherein the feeder substrate is attached to
an edge portion of the packaging bag so that the first radiating
element does not overlap with the second radiating element when
viewed in a plane in a direction perpendicular to a principal
surface of the feeder substrate.
3. A piece of merchandise including a wireless communication device
according to claim 1, wherein the feeder substrate includes an
inductance element that defines a matching circuit.
4. A piece of merchandise including a wireless communication device
according to claim 3, wherein the wireless IC chip includes first
and second input/output electrodes, and the inductance element
defining the matching circuit is connected between the first and
second input/output electrodes.
5. A piece of merchandise including a wireless communication device
according to claim 1, wherein the wireless IC chip processes a
high-frequency signal in a UHF-band.
6. A piece of merchandise including a wireless communication device
according to claim 1, wherein the second radiating element of the
packaging bag is an aluminum vapor deposited film.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to wireless communication devices and
particularly relates to wireless communication devices preferably
use in radio frequency identification (RFID) systems.
2. Description of the Related Art
In recent years, as merchandise information management systems,
RFID systems have been implemented in which communication using a
non-contact method employing an electromagnetic field is performed
between a reader/writer that generates an induction magnetic field
and an RFID tag (also referred to as a wireless communication
device) attached to a piece of merchandise so as to transmit
predetermined information therebetween. Such an RFID tag includes a
wireless IC chip that stores predetermined information and
processes a predetermined wireless signal, and an antenna that
transmits and receives a high-frequency signal.
As an antenna used in such an RFID tag, dipole antennas such as
those described in Japanese Unexamined Patent Application
Publication No. 2004-104344, Japanese Unexamined Patent Application
Publication (Translation of PCT Application) No. 2009-524363 and
International Publication No. 2007-013168 are known. Dipole
antennas can secure a comparatively large communication range, but
have a problem in that they have a large size. In recent years,
there has been a demand to "reduce RFID tags in size, despite this
reducing the communication range somewhat", but it has been
difficult to respond to and satisfy this demand using conventional
dipole antennas.
SUMMARY OF THE INVENTION
Accordingly, preferred embodiments of the present invention provide
a wireless communication device that includes two radiating
elements that define and function as a dipole antenna and is of a
small size.
A wireless communication device according to a preferred embodiment
of the present invention includes a first radiating element and a
second radiating element that define and function as a dipole
antenna, a feeder circuit coupled with the first radiating element
and the second radiating element, and a feeder substrate that is
provided with the feeder circuit.
The first radiating element is provided to the feeder
substrate.
The second radiating element is provided to a substrate other than
the feeder substrate.
A wireless communication device according to a second preferred
embodiment of the present invention includes a first radiating
element and a second radiating element that define and function as
a dipole antenna, a feeder circuit coupled with the first radiating
element and the second radiating element, and a feeder substrate
that is provided with the feeder circuit.
The first radiating element is provided to the feeder
substrate.
The feeder substrate includes a feeder terminal that is coupled
with the second radiating element.
In the wireless communication devices of the first and second
preferred embodiments of the present invention, the first radiating
element and the second radiating element are coupled with the
feeder circuit so as to define and function as a dipole antenna,
thus a required communication range is secured. The first radiating
element is provided to the feeder substrate, which is provided with
the feeder circuit, and is of a small size. Since the second
radiating element is provided to a substrate other than the feeder
substrate in the first preferred embodiment or the feeder terminal
of the feeder substrate is coupled with the second radiating
element in the second preferred embodiment, the second radiating
element can have a large size compared to another substrate having
a large area, such as a motherboard. Therefore, the main portion of
the wireless communication device including the feeder substrate
including the feeder circuit and the first radiating element has a
small size.
With various preferred embodiments of the present invention, among
the first radiating element and the second radiating element, which
define and function as a dipole antenna, the second radiating
element is separate from the wireless communication device and
therefore the wireless communication device is reduced in size.
The above and other elements, features, steps, characteristics and
advantages of the present invention will become more apparent from
the following detailed description of the preferred embodiments
with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A-1C illustrates a wireless communication device of a first
preferred embodiment of the present invention, where FIG. 1A is a
perspective view, FIG. 1B is a block diagram illustrating
functions, and FIG. 1C is an equivalent circuit diagram.
FIGS. 2A and 2B illustrates the wireless communication device of
the first preferred embodiment of the present invention, where FIG.
2A is a perspective view seen from the front side and FIG. 2B is a
perspective view seen from the back side.
FIG. 3 is an exploded perspective view of the wireless
communication device of the first preferred embodiment of the
present invention.
FIGS. 4A and 4B illustrate a wireless communication device of a
second preferred embodiment, where FIG. 4A is a functional block
diagram and FIG. 4B is an equivalent circuit diagram.
FIG. 5 is an equivalent circuit diagram of a wireless communication
device according to a third preferred embodiment of the present
invention.
FIG. 6 is an exploded perspective view of a wireless communication
device of a fourth preferred embodiment of the present
invention.
FIG. 7 is a sectional view of a wireless communication device of a
fifth preferred embodiment of the present invention.
FIG. 8 is a perspective view illustrating an example of mounting of
a wireless communication device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereafter, preferred embodiments of a wireless communication device
according to the present invention will be described with reference
to the accompanying drawings. In each of the drawings, components
and elements that are the same as each other will be denoted by the
same symbols and repeated description thereof will be omitted.
A wireless communication device 1A according to a first preferred
embodiment of the present invention is preferably used in a
UHF-band RFID system and as illustrated in FIGS. 1A-1C includes a
first radiating element 11, a second radiating element 12, a
wireless IC chip 20 that defines and functions as a feeder circuit,
and a matching circuit 30. The first radiating element 11 and the
matching circuit 30 are built into a feeder substrate 40 and the
wireless IC chip 20 is mounted on the feeder substrate 40. The
wireless IC chip 20 has a function of processing a high-frequency
signal, preferably is a silicon semiconductor integrated circuit
chip, includes for example a clock circuit, a logic circuit and a
memory circuit, and stores necessary information. The wireless IC
chip 20 is coupled with the first radiating element 11 and is
coupled with the second radiating element 12 via the matching
circuit 30.
The matching circuit 30, as illustrated in FIG. 1C, defines a
parallel resonance circuit including an inductor L1 and a capacitor
C1 and achieves impedance matching between the wireless IC chip 20
and the second radiating element 12. A matching circuit may also be
provided to achieve impedance matching between the wireless IC chip
20 and the first radiating element 11.
The first radiating element 11, as illustrated in FIG. 1C, defines
a series resonance circuit including an inductor L2, a capacitor C2
and an inductor L3. The second radiating element 12 preferably has
an elongated shape over a comparatively wide area on a substrate
other than the feeder substrate 40, for example, on a printed
wiring board 60 to be incorporated into a cellular phone. One end
of the second radiating element 12 is connected to a feeder
terminal 50 (refer to FIG. 3) provided on the back surface of the
feeder substrate 40, which will be described below, using solder or
the like.
The feeder substrate 40, as illustrated in FIG. 3, is a multilayer
substrate formed preferably by stacking a plurality of dielectric
layers or magnetic layers on top of one another. Connection
electrodes 42a to 42d are located on the front surface of a first
layer 41a, coil patterns 43 and 44 and a capacitor pattern 45,
which is connected to an end portion of the coil pattern 44, are
located on the front surface of a second layer 41b, and capacitor
patterns 46 and 47 are located on the front surface of a third
layer 41c. In addition, a capacitor pattern 48 and a coil pattern
49 are located on the front surface of a fourth layer 41d, and the
feeder terminal 50 and an NC terminal 51 are formed on the back
surface of the fourth layer 41d.
The layers 41a to 41d are stacked on top of one another, and as a
result the connection electrode 42a is connected to an end of the
coil pattern 43 by a via hole conductor 52a and is connected to the
capacitor pattern 46 by a via hole conductor 52b. The connection
electrode 42b is connected to an end of the coil pattern 44 by a
via hole conductor 52c. In addition, the other end of the coil
pattern 43 is connected to the capacitor pattern 48 by via hole
conductors 52d and 52e. The capacitor pattern 47 is connected to an
end of the coil pattern 49 by a via hole conductor 52f. The
capacitor pattern 48 is connected to the feeder terminal 50 by a
via hole conductor 52g. The NC terminal 51 only faces the coil
pattern 49 and an end portion of the coil pattern 49 is not
connected.
The coil pattern 43 defines the inductor L1, the coil pattern 44
defines the inductor L2 and the coil pattern 49 defines the
inductor L3. The opposing capacitor patterns 46 and 48 define the
capacitor C1 and the opposing capacitor patterns 45 and 47 define
the capacitor C2.
Various ceramic materials can be used as the dielectric layers or
the magnetic layers defining the feeder substrate 40 or resin
materials may be used. In the case where the feeder substrate 40 is
formed of a ceramic material, the conductor patterns provided on
the individual layers can be formed preferably by printing a
conductive paste, for example. In the case where the feeder
substrate 40 is formed of a resin material, the conductor patterns
can be formed preferably by etching a metal foil or a metal film,
for example.
That is, in this first preferred embodiment, the feeder substrate
40 is a multilayer substrate and the first radiating element 11 and
the matching circuit 30 are built into the feeder substrate 40.
However, it is not necessary for the all of the coil patterns to be
built into the feeder substrate 40.
The wireless IC chip 20 includes input/output electrodes 21a and
21b (refer to FIG. 1B) that receive a high-frequency signal as a
potential difference. These input/output electrodes 21a and 21b are
connected to the connection electrodes 42a and 42b provided on the
feeder substrate 40 via solder bumps or the like, one input/output
electrode 21a is connected to the first radiating element 11
(inductor L2), and the other input/output electrode 21b is
connected to the second radiating element 12 via the matching
circuit 30 (inductor L1, capacitor C1 and feeder terminal 50).
In this wireless communication device 1A, the first radiating
element 11 and the second radiating element 12 are connected to the
wireless IC chip 20 and function as a dipole antenna. When the
distance is long, transmission and reception of high-frequency
signals with a reader/writer for an RFID system is performed by
mainly utilizing the second radiating element 12. When the distance
is short, transmission and reception of high-frequency signals is
performed by mainly utilizing the first radiating element 11.
The first radiating element 11 is built into the feeder substrate
40 and the second radiating element 12 is provided on the printed
wiring board 60, which is a substrate that is other than the feeder
substrate 40. Therefore, the practical size of the wireless
communication device 1A is the size of the feeder substrate 40 and
a reduction in size is achieved. In addition, the feeder substrate
40 is mounted on the second radiating element 12, but is only
connected to the second radiating element via the feeder terminal
50 (one place connection) and therefore the positional accuracy
required in mounting is relaxed.
Second Preferred Embodiment
In a wireless communication device 1B of a second preferred
embodiment of the present invention, as illustrated in FIGS. 4A and
4B, the input/output electrodes 21a and 21b of the wireless IC chip
20 are connected to the matching circuit 30. The matching circuit
30 includes an inductor L4, in addition to the inductor L1 and the
capacitor C1 described in the first preferred embodiment. One
input/output electrode 21a of the wireless IC chip 20 is connected
to a connection point between the inductors L4 and L2 and the other
input/output electrode 21b is connected to a connection point
between the inductor L4 and a parallel resonance circuit (inductor
L1 and capacitor C1).
The rest of the configuration of the second preferred embodiment
preferably is the same or substantially the same as that of the
first preferred embodiment and the operational effects are the same
as that described in the first preferred embodiment. The inductor
L4 added to the matching circuit 30 defines and functions as an
element that adjusts the degree of coupling between the first
radiating element 11 and the second radiating element 12.
Third Preferred Embodiment
In a wireless communication device 1C of a third preferred
embodiment of the present invention, as illustrated in FIG. 5, the
configuration of the matching circuit 30 is changed. The matching
circuit 30 includes a series resonance circuit including an
inductor L5 and a capacitor C3 and a series resonance circuit
including an inductor L6 and a capacitor C4, and these two
resonance circuits are connected to each other via an inductor L7.
The inductors L5 and L6 are wound in opposite directions, are
arranged adjacent to each other, and are electromagnetically
coupled with each other. In addition, the inductor L4 that adjusts
the degree of coupling described in the second preferred embodiment
is connected between the first radiating element 11 and the feeder
terminal 50.
One input/output electrode 21a of the wireless IC chip is connected
to one end of the inductor L6 and the other input/output electrode
21b is connected to one end of the inductor L5. In addition, a
connection point between the capacitor C4 and the inductor L4 is
connected to the first radiating element 11 (inductor L2) and a
connection point between the capacitor C3 and the inductor L4 is
connected to the second radiating element 12 via the feeder
terminal 50.
The rest of the configuration of the third preferred embodiment
preferably is the same or substantially the same as that of the
first preferred embodiment and the operational effects are the same
as that described in the first preferred embodiment. In the
matching circuit 30, the first and second radiating elements 11 and
12 operate at the different resonant frequencies possessed by the
two series resonance circuits and as a result the communication
band is widened. In addition, this preferred embodiment is the same
as the second preferred embodiment in the point that the inductor
L4 adjusts the degree of coupling between the first radiating
element 11 and the second radiating element 12. The inductor L7
matches an impedance of the feeder terminal.
Fourth Preferred Embodiment
In a wireless communication device 1D of a fourth preferred
embodiment of the present invention, as illustrated in FIG. 6, the
feeder terminal 50 is built into the lowermost layer of the feeder
substrate 40 and the back surface of the feeder substrate 40 is
adhered to the second radiating element 12 so as to couple the
feeder terminal 50 and the second radiating element 12 with each
other through a capacitor C5. The feeder terminal 50 is located on
the front surface of the fifth layer 41e of the feeder substrate
40. The rest of the configuration of the feeder substrate 40
illustrated in FIG. 6 preferably is the same or substantially the
same as that illustrated in FIG. 3.
In this fourth preferred embodiment, except the matching circuit 30
and the second radiating element 12 being coupled with each other
through the capacitor C5, the configuration preferably is the same
or substantially the same as that of the first preferred
embodiment. Therefore, the operational effects of the fourth
preferred embodiment are substantially the same as that of the
first preferred embodiment, but in particular the anti-surge
performance is improved by the capacitor C5.
Fifth Preferred Embodiment
In a wireless communication device 1E of a fifth preferred
embodiment of the present invention, as illustrated in FIG. 7, the
wireless IC chip 20 is arranged in a center portion of the feeder
substrate 40, which includes multiple layers, the first radiating
element 11 is arranged in a top portion, and the matching circuit
30 is arranged in a bottom portion. The wireless communication
device 1E is adhered to the printed wiring board 60 with adhesive
layers 62. An equivalent circuit of this preferred embodiment is
preferably the same as that of the first preferred embodiment
illustrated in FIG. 1C. Therefore, the operational effects of the
fifth preferred embodiment are substantially the same as that of
the first preferred embodiment. In particular, in the fifth
preferred embodiment, the first radiating element 11 is arranged on
the front surface side of the feeder substrate 40 and therefore
communication performance is improved when the antenna of a
reader/writer is brought closer to the wireless communication
device 1E. In addition, the wireless IC chip 20 is interposed
between the matching circuit 30 and the first radiating element 11,
and as a result isolation of the matching circuit 30 and the first
radiating element 11 from each other is improved. In the sectional
view of FIG. 7, illustration of hatching is omitted so as to avoid
complexity. The electrode 51 is for mounting the feeder substrate
40, but even if omitted, the wireless communication device 1E would
still function as an RFID tag. In this case, the electrode (feeder
terminal) 50 can be made larger and the positional accuracy
required in mounting is relaxed.
The wireless communication devices 1A to 1E of the preferred
embodiments have been described as preferably being mounted on the
printed wiring board 60. However, other than this, the wireless
communication device can be mounted on a variety of pieces of
merchandise or on the packaging of a piece of merchandise. In FIG.
8, the wireless communication device 1A is illustrated as being
mounted on a packaging bag 70 of a food product. The packaging bag
70 has aluminum vapor deposited over its entire surface and the
wireless communication device 1A is affixed to an edge portion,
which is a seam portion 71, of an aluminum vapor deposited film 72
(functioning as the second radiating element).
Other Preferred Embodiments
Wireless communication devices according to the present invention
are not limited to the above-described preferred embodiments and
can be modified in various ways within the scope of the gist of the
present invention.
In particular, the first radiating element and the matching circuit
can include a variety of circuit elements and are not limited to
circuit configurations including inductors and capacitors as
described in the preferred embodiments. The second radiating
element can have a variety of shapes such as a meandering shape and
a coil shape, for example. In addition, coupling of the first and
second radiating elements and the wireless IC chip may be any of
magnetic field coupling, capacitive coupling, electric field
coupling, electromagnetic field coupling and direct current
coupling.
The wireless IC chip may include four input/output electrodes so as
to be suitable for use with two dipole antennas. In addition, the
feeder substrate may take the form of a separate substrate as a
standalone unit or a rewiring layer to connect a terminal provided
on a mounting surface of a wireless IC chip may double as the
substrate.
As described above, preferred embodiments of the present invention
can be used in wireless communication devices and are particularly
excellent in that a wireless communication device can be reduced in
size.
While preferred embodiments of the present invention have been
described above, it is to be understood that variations and
modifications will be apparent to those skilled in the art without
departing from the scope and spirit of the present invention. The
scope of the present invention, therefore, is to be determined
solely by the following claims.
* * * * *